水下无人系统学报

Integrated Platform and Its Key Technologies for Torpedo General Mul-tidisciplinary Design Optimization

HUANG Qiao-gao, PAN Guang, WU Lin-li

2012, 20(2): 081-85. doi: 10.11993/j.issn.1673-1948.2012.02.001

[Abstract](1537) [PDF 205KB](613)

Abstract:
The technical bottlenecks in torpedo general design and application trend of multidisciplinary design optimi-zation (MDO) are analyzed. Based on the technologies about project management, process management, data manage-ment, knowledge engineering and multidisciplinary design optimization, a concept of integrated platform for torpedo general multidisciplinary design optimization is presented. The system structure and the key technologies of the platform are discussed in detail. This research may provide a reference for further study and establishment of the integrated plat-form for torpedo general multidisciplinary design optimization.

A Structured Grid Processing Method for Torpedo with Varying Angle of Rudder

LU Rui, TAN Kun, CAI Wei-jun

2012, 20(2): 086-89. doi: 10.11993/j.issn.1673-1948.2012.02.002

[Abstract](1117) [PDF 1041KB](608)

Abstract:
This paper proposes a quick and efficient processing method of multi-block structured grid for torpedo with cross-shaped all-movable rudder or cross-shaped fin-tip rudder. Making use of structured grid, which is advantageous to exquisitely control near-wall′s mesh quality and achieve high solution precision, a method for dividing structured grid based on multi-block technology is presented. Local flow-field zones of fin or rudder are separated from whole torpedo domain to form multiple blocks, and structured grid is divided within each block by using independent coordinate frame. Then the grid of computation domain of whole flow-field is constructed. This method can simplify grid-dividing process, shorten grid-dividing time, and improve calculation efficiency and precision. Simulation result coincides with tunnel test one, indicating the proposed method is available for the geometries with small movement, such as rotation around a fixed axis.

Interference Mechanism and Simulation on Underwater Explosion Against Passive Acoustic Homing Torpedo

ZENG Xing-xing, GU Xiao-hui, CHENG Feng-sheng, NIAN Gang

2012, 20(2): 090-94. doi: 10.11993/j.issn.1673-1948.2012.02.003

[Abstract](1378) [PDF 300KB](637)

Abstract:
Acoustic interference ammunition is a kind of new concept munitions. To verify its effect of underwater explosion signal on acoustic homing torpedo, we establish an acoustic countermeasure model by making use of the features of high source-level and wide bandwidth of the signal for a ship to evade acoustic homing torpedo, and translate countermeasure problem into a nonlinear and constrained target optimization function by mathematical optimization methods. As a result, the optimal evasion angle and the perfect location of acoustic interference ammunition are obtained, and smaller variation of opti-mal launch angle is achieved. Simulation results show that acoustic interference ammunition can interfere acoustic homing torpedo effectively under optimal launching condition.

Error Analysis of Green′s Function Sampled in K-space for Forward Reconstruction

TANG Bo, YUAN Bing-cheng, XU Yu

2012, 20(2): 095-99. doi: 10.11993/j.issn.1673-1948.2012.02.004

[Abstract](1029) [PDF 554KB](595)

Abstract:
During the near-field acoustic holographic reconstruction, tremendous errors will appear when using Green′s function sampled in K-space for long distance forward reconstruction, and conventional window function cannot restrain the error efficiently. In this paper, the error is analyzed to be generated by spectrum leakage and edge Gibbs phenomenon derived from amplitude discontinuity of Green′s function sampled in K-space, hence a corresponding method for changing the cut-off wave number of window function is represented to smooth the amplitude discontinuity and further to restrain the error. Simulation result shows that the improved window function can obviously reduce the error in the holographic aperture, and the present method is efficient in restraining the error generated by spectrum leakage and Gibbs phenomenon derived from amplitude discontinuity of Green′s function sampled in K-space.

Integrated Detection Method of Active Underwater Acoustic Fuze Echo

HU Qiao, BAI Zhi-ke, ZHU Jian, WANG Wei, XIAO Su-juan

2012, 20(2): 100-106. doi: 10.11993/j.issn.1673-1948.2012.02.005

[Abstract](996) [PDF 415KB](621)

Abstract:
To accurately detect active underwater acoustic fuze in complicated natural interferences, a novel integrated detection method is proposed. In this method, macro- and micro-features of target echo signals and interferences (such as reverberation) are analyzed; the intrinsic mode functions (IMFs) from original signals received by fuze system are achieved via the improved empirical mode decomposition(EMD) approach to separate the target echo signal from the reverberation; and the statistics of variance of instantaneous frequency detection and energy detection are obtained from IMFs and are combined to form an integrated detector for optimally detecting underwater acoustic fuze. Lake tests indicate that the proposed method exhibits better performance in underwater acoustic fuze detection, compared with such commonly used detection methods as energy detection method and variance of instantaneous frequency de-tection method.

Propagation Property of Short Range High-frequency Radiated Noise Con-sidering Sea Surface Scattering Effect

ZHAO Jun, WU Di-xiao

2012, 20(2): 107-110. doi: 10.11993/j.issn.1673-1948.2012.02.006

[Abstract](1142) [PDF 261KB](669)

Abstract:
Aiming at the urgent demand of constructing short range anti-torpedo system, we investigate the propagation property of torpedo′s near-field high-frequency radiated noise. We analyze the acoustic scattering properties of rough sea surface using the small slope approximation(SSA), give the expression of second-order to fourth-order SSA bistatic scattering coefficient for the rough sea surface with Gaussian distribution, and discuss the variation law of second-order SSA bistatic scattering coefficient with different sea surface roughness and incidence angle. The scattering field of un-derwater high-frequency radiated noise is calculated by using the SSA bistatic scattering coefficient. Simulation result shows that the scattering effect of sea surface should be considered in studying the propagation property of high- fre-quency radiated noise with source/receiver near sea surface.

A Formation Control Algorithm for Multiple Autonomous Underwater Ve-hicles Based on Jacobi Shape Theory

ZHANG Jing, YANG Hui-zhen, HAO Li-li, KANG Feng-ju

2012, 20(2): 111-116. doi: 10.11993/j.issn.1673-1948.2012.02.007

[Abstract](1363) [PDF 460KB](713)

Abstract:
Dynamics modeling and formation control of multiple autonomous underwater vehicles (MAUVs) system are ad-dressed. Based on dynamics and kinematics models of a single AUV, a horizontal dynamics model of MAUV system is estab-lished by applying the Jacobi geometric vector. With the hydrodynamic parameters of the typical underwater vehicle’s omni-directional intelligent navigator (ODIN), the formation dynamics model is reasonably simplified and decoupled into three linear subsystems——formation shape, formation movement (i.e. movement of the formation center), and Vehicle orien-tation subsystem. Motion controller and steering controller are designed for the decoupled linear subsystem by using the linear state feedback approach. Simulation results demonstrate that the algorithm can control the formation center of MAUV system to track known path while keeping formation shape.

Modeling and Simulation of Longitudinal Movement Control for Anti-torpedo Torpedo Based on Variable Structure Control

ZHANG Xi-yong, WANG Shu-zong, LI Zong-ji

2012, 20(2): 117-119. doi: 10.11993/j.issn.1673-1948.2012.02.008

[Abstract](1421) [PDF 389KB](617)

Abstract:
This paper addresses the application of variable structure control technology to control of anti-torpedo torpedo, and establishes a mathematical model and a controlling model of torpedo′s longitudinal movement. Simulation analysis shows that the control system has good dynamic characteristic, high robustness and system stability, and strong anti-interference capacity. Conclusion is drawn that variable structure control technology can resolve parameter’s uncer-tainty and anti-interference problems existing in longitudinal movement control of anti-torpedo torpedo.

Investigation on Working Performance of Water-jet Gas Turbine Using Solid Propellant

QIAO Hong, HAN Xin-bo, YI Jin-bao, LI Hong-wei

2012, 20(2): 120-124. doi: 10.11993/j.issn.1673-1948.2012.02.009

[Abstract](1449) [PDF 388KB](653)

Abstract:
The working principle and heat-to-power conversion of a water-jet gas turbine using solid propellant was in-vestigated, the cavitation performance of the axial pump was analyzed, and the turbine′s heat-to-power conversion effi-ciency and propulsive efficiency were calculated. The results show that the anti-cavitation performance of the axial pump at high rotary speed is better than that of the conventional screw propeller, and matched operation of the gas tur-bine and the axial pump can be implemented by reasonable design of the working parameters of gas turbine.

Dynamic Stiffness Calculation Method for Rubber Ring Isolator

JIN Jing, ZHANG Zhen-shan, XIONG Xin

2012, 20(2): 125-128. doi: 10.11993/j.issn.1673-1948.2012.02.010

[Abstract](975) [PDF 184KB](741)

Abstract:
Based on the conventional calculation method of dynamic stiffness for rubber ring isolator, a new calculation method is presented by simulating principal components of the isolator as a whole. Firstly, a finite element model of rubber ring isolator is established including metal and rubber parts. Then, sinusoidal excitations with different fre- quencies are exerted on isolator ring according to its actual force condition. As a result, dynamic stiffness in different direction is obtained by simulation. By comparing with static stiffness of isolator and dynamic stiffness of rubber, some variation rules of dynamic stiffness of the isolator are observed, which may benefit vibration analysis of engine and simplification of rubber ring isolator.

Fault Diagnosis Method of Torpedo Guidance System Based on Case-based Reasoning

HAN Yun-dong, ZHOU Ming, TONG Yan, MA Hai-rui

2012, 20(2): 129-133. doi: 10.11993/j.issn.1673-1948.2012.02.011

[Abstract](996) [PDF 233KB](576)

Abstract:
To overcome the shortcomings of traditional rule-based reasoning(RBR), this study introduced case-based reasoning (CBR) into torpedo guidance fault diagnosis system. The diagnosis strategy of CBR was analyzed, and the two-level case retrieval mechanism and the algorithm were explained. The design of the torpedo guidance fault diagnosis system based on CBR was particularly described from three aspects, i.e., description of case, structure of diagnosis sys-tem, and process of working flow. And this system was developed with VB6.0. Fault case analysis shows that the pro-posed system can enhance the efficiency and correctness of fault diagnosis of torpedo guidance system.

Simulation of Convoy Warship Formation Defending Against Acoustic Homing Torpedo with Rocket Assisted Acoustic Decoy

LIU Feng, SHEN Zhi-he

2012, 20(2): 134-138. doi: 10.11993/j.issn.1673-1948.2012.02.012

[Abstract](1017) [PDF 381KB](578)

Abstract:
To address a convoy warship formation defending against an acoustic homing torpedo, the process of single warship trapping an incoming torpedo by using a rocket assisted acoustic decoy is analyzed, consequently a mathe- matical model about an acoustic homing torpedo attacking a warship formation and a rocket assisted acoustic decoy trapping an incoming torpedo is established. The tracking trajectory of the torpedo in attacking a warship formation is simulated, and the processes of trapping a torpedo by the decoys from different convoy warships are analyzed. As a re-sult, some torpedo postures with which the torpedo can successfully hit the warship formation are obtained, and the best launching position of the decoy for effectively protesting the formation in a typical situation is achieved.

A Bayesian Fusion and Evaluation Method for Operational Reliability of Torpedo in Sea Trial Based on Credibility of Prior Information

XING Guo-qiang, YAN Xue, HOU Dai-wen

2012, 20(2): 139-142. doi: 10.11993/j.issn.1673-1948.2012.02.013

[Abstract](895) [PDF 261KB](541)

Abstract:
Operational reliability is one of the important indexes for evaluating operational effectiveness of a rocket- assisted torpedo. However, the evaluation of operational reliability has the disadvantages of small test sample and high risk. To overcome the disadvantages, we introduce the evaluation test technology for tactical missile into fusing and evaluating the index with prior information, and present a posterior-weighted Bayesian fusion and evaluation method for torpedo′s operational reliability in sea trial based on the credibility of the prior information to prevent the test informa-tion to be possibly inundated with much prior information. Example analysis shows that our method can accurately evaluate the operational reliability of torpedo in sea trial.

Hardware-in-the-loop Simulation System of UUV Obstacle Avoidance Based on Binocular Vision

YAN Zhe-ping, JIANG Ling, WANG Xiao-juan, ZHAO Yu-fei

2012, 20(2): 143-148. doi: 10.11993/j.issn.1673-1948.2012.02.014

[Abstract](1738) [PDF 411KB](774)

Abstract:
The sea trials for the obstacle avoidance research of an unmanned underwater vehicle (UUV) are expensive and high-risk. To facilitate the research of automatic obstacle avoidance of an UUV in laboratory, a hardware- in-the-loop simulation system of UUV obstacle avoidance has been developed based on binocular vision, where the multi-degree of freedom test platform is used to simulate the motion of the UUV, and the double-stereo vision system is used to simulate forward looking sonar. In this paper, the structure and data stream of the system are discussed. The key technologies for vision subsystem and the software scheme for UUV model subsystem are also described. Joint simula-tion tests were conducted by adopting rule-based obstacle avoidance approach. Experimental results show that the sys-tem has the advantages of simple structure and convenient application, and it can be used in demonstration, validation, and evaluation of obstacle avoidance path plan.

An Acoustic-Optical Compound Guidance Simulation Platform for Complete Trajectory of Torpedo Based on Ethernet

LI Bin, ZHENG Wei, WAN Ya-min

2012, 20(2): 149-152. doi: 10.11993/j.issn.1673-1948.2012.02.015

[Abstract](1502) [PDF 1111KB](585)

Abstract:
Using acoustic-optical compound guidance mode can improve the target detection range and guidance precision of a torpedo in complex underwater acoustic field, compared with the conventional single guidance mode. We researched the proc-ess before firing a torpedo, the operational posture, the wire guidance method, the ship wake model, and the model for wake homing test, and constructed an acoustic-optical compound guidance simulation platform for complete trajectory of a torpedo based on Ethernet to provide technical support for the hardware-in-loop simulation platform. On this acoustic-optical com-pound guidance simulation platform, such studies as application method and performance evaluation of the torpedo with acoustic-optical compound guidance can be conducted.

Analysis on Transition Characteristics of Echoes from Submarine Based on Highlight Model

XU Yu, YUAN Bing-cheng, TANG Bo

2012, 20(2): 153-156. doi: 10.11993/j.issn.1673-1948.2012.02.016

[Abstract](1545) [PDF 300KB](589)

Abstract:
Transition characteristics of echoes from submarine are essential in studying submarine detection and acoustic countermeasure. Calculating echo strength from an underwater target versus distance is an effective method for analyz-ing transition characteristics of echoes from underwater targets. Theoretical analyses and experiments have shown that under high frequency, echo from any complex target can be considered a coherent superposition of waves from high-lights. A novel algorithm is presented in this paper based on a highlight model to calculate the submarine echo strength in different distance, and to analyze the transition characteristics of echoes from a submarine. Simulation results show that the proposed method is simpler and more efficient compared with the planar element method.

Finite Element Analysis on Acoustic Characteristic of Double Bubble in Ship Wake

ZHANG Qun, WANG Ying-min

2012, 20(2): 157-160. doi: 10.11993/j.issn.1673-1948.2012.02.017

[Abstract](1557) [PDF 605KB](626)

Abstract:
Acoustic characteristic, which mainly depends on bubble, is one of the most important characteristics of ship wake. In this paper, the active acoustic characteristic of single bubble in ship wake is analyzed, and an elastic sphere shell′s active acoustic reflection / scattering characteristic model of single bubble is established. A finite element model of double bubble is also set up combining the acoustic characteristic of bubble in different radius and the distribution analy-sis of bubbles in ship wake. Finite element analysis method is used to analyze the displacement varying with frequency under cyclic loading condition, thus the bubbles′ resonant frequencies are obtained. The distribution of double bubble field under incident active sound source is computed to obtain the active acoustic reflection / scattering characteristic of double bubble.

2012 Vol. 20, No. 2

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